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HER2-Positive Breast Cancer

All new breast cancers are tested for an excess of human epidermal growth factor receptor 2 (HER2). About one out of every five breast cancers have too many HER2 receptors. HER2 status guides how we treat breast cancer. At the Abramson Cancer Center, our experts provide precise diagnosis and testing to get you the most effective treatment for breast cancer.

What Is HER2-Positive Breast Cancer?

All breast cells have HER2 proteins, which are receptors that control how the cells grow and divide. When breast tissue has extra HER2 receptors (overexpression), breast cells can multiply too quickly. The growth may become uncontrolled and lead to a tumor.

Breast cancer identified as HER2-positive tends to grow faster, spread (metastatic breast cancer) and come back (recur). While HER2-positive cancer may be aggressive, it also responds better to breast cancer treatment that targets HER2 protein. There are no unusual symptoms or risk factors associated with HER2-positive breast cancer, although some studies suggest that HER2-positive status is more common among younger women.

Testing for HER2 Status

Our breast pathologists test all breast tumor tissue using a sample taken during a biopsy or surgery. There are several tests that examine HER2. The most common tests used include:

  • Immunohistochemistry (IHC) test: This test measures the amount of HER2 proteins found on breast cancer cells. The score will either be 0 to 1+ (HER2 negative), 2+ (borderline) or 3+ (HER2-positive).
  • Florescent in situ hybridization (FISH) test: If an IHC test is borderline, this test provides more information about HER2. It looks for extra copies of the HER2 gene (which produces the HER2 protein). The result will be either positive or negative.

Breast tissue is also tested for hormone receptors (estrogen and progesterone). If a tumor tests positive for hormone receptors in addition to HER2, breast cancer may respond to hormone therapy. Cancer that tests negative for hormone receptors and HER2 is called triple negative breast cancer.

Why Choose the Abramson Cancer Center for HER2-Positive Breast Cancer?

We provide comprehensive breast cancer care for every stage and type of breast cancer. Our specialized providers offer patient-centered, advanced treatment for people with HER2-positive breast cancer. The benefits of cancer care at the Abramson Cancer Center include:

  • Precise diagnosis: The accuracy of HER2 tests often depends on the pathologist. Our specialized breast cancer pathologist works only with breast tissue. We provide you with the most accurate interpretation of your HER2 test.
  • Leaders in targeted therapy: We are nationally recognized for our role in the development of targeted therapies. Our research and clinical trials continue to advance promising treatments for HER2-positive breast cancer.
  • Attention to breast cancer recurrence: Our 2-PREVENT Breast Cancer Transitional Center of Excellence helps you prevent, identify and manage breast cancer recurrence associated with HER2-positive breast cancer.
  • Care where you live: All Penn Medicine locations provide expert breast cancer diagnosis, testing and treatment. Specialists across the network work together to get you personalized care.

Our Approach to HER2-Positive Treatment

We know what fuels the growth of HER2-positive breast cancer. Our specialized oncologists use precision medicine that targets HER2 receptors along with standard breast cancer treatment to design individualized care. Treatment for HER2-positive breast cancer may include: